Well Judge simply... WHAT IS DIFFERENT TO WHEN THEY WERE WINNING?

The 4yr olds legs are probably running out of steam, but the 3yr old..
Whats its race name? Because has it been in constant work? if so spell it for a month, take it to the track, maybe give some incentive to it but DO NOT run it. Then head to a local free gallop place and slip it behind a drag lure for 100m.

Itll most likely go bonkers and chase its guts out. Then move it back and give it a 300-350m trial somewhere and judge its trial time to see if its still got it.